1. Technical Field
The present application relates to a drill and a method for the production thereof.
2. Background Information
Background information is for informational purposes only and does not necessarily admit that subsequently mentioned information and publications are prior art.
The present application relates to a modular drilling tool, comprising a carrier body and a cutting unit that can be fastened thereto, the carrier body extending along a carrier body longitudinal axis, being realized substantially as a circular cylinder having a carrier body radius, and having a chip groove and a run-out or discharge edge that extends along the chip groove. The present application furthermore relates to a method for producing such a drilling tool.
Modular drilling tools are known in a variety of embodiments, which differ, for example, in their holding of separately realized cutting units. For example, soldered-in hard-metal cutting tips or complete drill bits are used as cutting units. There are known, moreover, changeable cutting units, such as reversible cutting plates, which are held on the carrier body of the drilling tool by means of screws, or such as cassettes, comprising reversible cutting plates, which are connected to the carrier body through positive holding. There are additionally known exchangeable drill bits, which are fastened to the carrier body, for example, by means of screws or through clamping or through positive fit. Common to these modular drilling tools is the division into the cutting unit and the carrier body. The carrier body has a front region, comprising chip grooves, and a shank region, for receiving the drilling tool into a clamping device of a machine tool.
Some tools, realized as drilling tools having reversible cutting plates, inner chip grooves and outer chip grooves which are shaped in such a way that they merge into one another in the middle to rear region of the tool. In the case of these tools, the chip groove has stiffening beads on both walls.
Fluctuations of the parameters in the drilling process result in the formation of differing chip shapes. In addition to the wanted fragmental chip pieces, unwanted helical chips and helical fragmental chips can also be produced. These chip portions, when being removed from the cutting edge of the drilling tool via the chip groove, continually or substantially continually cause contact with the wall of the bore, resulting in scores that impair the surface quality of the bore produced.
Moreover, a continual or substantially continual occurrence is that, at the run-out edge, chips become jammed between the wall of the bore and the rear of the drill, and thereby cause increased torsional loading of the drill body. In this situation, there is also an increased thermal loading of the drill, since the heat produced during cutting is also taken away from the base of the bore with the chips. In extreme cases, such a jammed-in chip thereby becomes welded to the wall of the bore.